7. Application layer-Responsible for initiating or services the request. e.g SMTP, DNS, HTTP, and Telnet 6. Presentation layer-Formats the information so that it is understood by the receiving system e.g Compression and encryption depending on the implementation 5. Session layer– Responsible for establishing, managing, and terminating the session e.g NetBIOS 4. Transport layer-Breaks information into [...]

AAA debug radius debug tacacs show aaa-server protocol PROTOCOL_NAME test aaa-server Access Control Lists show access-list show run | include ACCESS_LIST_NAME show run object-group show run time-range Application Inspection show conn state STATE_TYPE detail show service-policy Configuring Interfaces show firewall show int show int ip brief show ip show mode show nameif show run interface [...]

In computer networking, the default route is a setting on a computer that defines the packet forwarding rule to use when no specific route can be determined for a given Internet Protocol (IP) destination address. All packets for destinations not established in the routing table are sent via the default route. The default route generally [...]

Simple Network Management Protocol (SNMP) is an application–layer protocol defined by the Internet Architecture Board (IAB) in RFC1157 for exchanging management information between network devices. It is a part of Transmission Control Protocol⁄Internet Protocol (TCP⁄IP) protocol suite. SNMP is one of the widely accepted protocols to manage and monitor network elements. Most of the professional–grade [...]

ARP stands for Address Resolution Protocol. When you try to ping an IP address on your local network, say 192.168.1.1, your system has to turn the IP address 192.168.1.1 into a MAC address. This involves using ARP to resolve the address, hence its name. Systems keep an ARP look-up table where they store information about [...]

A load balancer is a device that acts as a reverse proxy and distributes network or application traffic across a number of servers. Load balancers are used to increase capacity (concurrent users) and reliability of applications. They improve the overall performance of applications by decreasing the burden on servers associated with managing and maintaining application and [...]

The Three-way handshake begins with the initiator sending a TCP segment with the SYN control bit flag set. TCP allows one side to establish a connection. The other side may either accept the connection or refuse it. If we consider this from application layer point of view, the side that is establishing the connection is [...]

The SPAN feature, which is sometimes called port mirroring or port monitoring, selects network traffic for analysis by a network analyzer. The network analyzer can be a Cisco SwitchProbe device or other Remote Monitoring (RMON) probe.

Check the system status myfirewall/pri/act# show firewall Firewall mode: Router myfirewall/pri/act# show version Cisco Adaptive Security Appliance Software Version 9.1(1) Device Manager Version 7.1(1)52 Compiled on Wed 28-Nov-12 10:38 by builders System image file is “disk0:/asa911-k8.bin” Config file at boot was “startup-config” myfirewall up 218 days 1 hour failover cluster up 5 years 10 days [...]

Device management: Show general system-health information –> show system info Show percent usage of disk partitions –> show system disk-space Show the maximum log file size –> show system logdb-quota Show running processes –> show system software status Show processes running in the management plane –> show system resources Show resource utilization in the dataplane [...]

For starting or stopping firewall services cpstop-Stop all Check Point services except cprid . You can also stop specific services by issuing an option with cpstop. For instance cpstop FW1 stops FW-1/VPN-1 or use cpstop WebAccess to stop WebAccess. cpstart-Start all Check Point services except cprid . cpstart works with the same options as cpstop [...]